Certain cannulas have surgical tools located within the cannula for performing surgical operations on a vessel of interest. The cannula is inserted into a surgical site with the distal end of the cannula positioned near the vessel of interest. An endoscope positioned within the cannula allows the surgeon to view the target area, and allows the surgeon to position the surgical tool correctly. One common procedure is to ligate a vessel or other tissue by tightening a suture loop tied as a slipknot on the vessel before transection to provide hemostasis to the vessel.
However, surgeons encounter several difficulties in ligation procedures. In one ligation procedure, a second incision must be made at the opposite end of the vessel of interest to ligate and transect the vessel. Multiple incisions are invasive and should be minimized if possible. In order to avoid this second incision, some conventional methods require tying a suture loop around the vessel, and pushing the loop along the vessel with a knot pusher until the opposite end is reached. Then, the loop is tightened to provide ligation. However, this procedure is difficult because the slipknot often catches on stumps of cut tributaries or other tissue, and then constricts around the vessel at the wrong position. Also, there is no easy method for transecting the vessel after the suture loop is tied to the vessel without potentially prematurely severing the suture.
Thus, a device and method is needed to allow remote, one-incision, ligation of a vessel which allows a suture loop to be moved reliably to the site of interest, and ensures that the transection instrument is able to transect the vessel, and cut the suture.